1. Field of the Invention
The present invention relates to an outboard motor and a watercraft including the same, and specifically to an outboard motor including a V-shaped 4-cycle engine which includes a catalyst to purify exhaust gas, and a watercraft including such an outboard motor.
2. Description of the Related Art
An engine of an outboard motor is generally structured to discharge exhaust gas into water. However, the exhaust gas, if discharged as it is, causes air pollution. Thus, a catalyst for purifying exhaust gas is provided in the engine of the outboard motor.
JP 6-159053 describes a V-shaped 2-cycle engine including a left bank extending in an obliquely rearward and leftward direction and a right bank extending in an obliquely rearward and rightward direction and also having a catalyst located to the left of the left bank and also to the right of the right bank. In more detail, an exhaust case having a path extending downward is formed to the left of the left bank and also to the right of the right bank. The catalyst is accommodated in each of the exhaust cases.
In the left bank, an exhaust port open in an obliquely rearward and rightward direction is formed. An exhaust pipe connected to the exhaust port once extends upward, passes above the left bank, and is connected to the exhaust case located to the left of the left bank. In the right bank, an exhaust port open in an obliquely rearward and leftward direction is formed. An exhaust pipe connected to the exhaust port once extends upward, passes above the right bank, and is connected to the exhaust case located to the right of the right bank.
In the above-described V-shaped engine, the exhaust pipes in the left bank and the right bank are both formed to pass above the respective banks, and therefore are long. In the above-described V-shaped engine, a large space is occupied by the exhaust pipes, which prevents a decrease in the size of the outboard motor.